Electrical relays



Feb. 11, 1964 H. o. WELLS ETAL 3,121,148

ELECTRICAL RELAYS Filed Dec. 28, 1960 2 Sheets-Sheet 1 1 iiiiii' T ll i a 1|! 46 345 i i 45 .mnh. 44 44 H v /3 A TTORNEYS Feb. 11, 1964 H. c). WELLS ETAL ELECTRICAL RELAYS 2 Sheets-Sheet 2 Filed Dec.. 28, 1960 a base 110 and a cover '11.

3,121,148 ELECTRICAL RELAYS Hugh Otis Wells, Princeton, and Ralph Engel Probert, Evansville, Ind., assignors to American Machine 8; Foundry Company, a corporation of New Jersey Filed Dec. 28, 196i), Ser. No. 78,910 4 Claims. (Cl. 200-93) This invention relates to improvements in electrical relays and, while not limited thereto, is particularly applicable to miniature relays.

[n recent years, there has been an increasing demand for miniature relays. Many applications require not only that such relays be compact but also that they be capable of withstanding the effects of relatively severe vibration and shock.

Accordingly, one of the objects of this invention is to provide an improved relay which is highly resistant to the effects of shock and vibration.

Another object is to provide a highly compact relay having a plurality of terminal pins arranged so that the relay can readily be plugged into a printed circuit board, the relay then occupying space which extends for only a relatively short distance in a direction perpendicular to the plane of the board.

A further object of this invention is to provide, in a relay of the type having a pair of e-lectromagnets and a permanent magnet, novel and improved means for rigidly mounting the electromagnets and the permanent magnet on a supporting base. I

In order that the manner in which these and other objects are attained, in accordance with the invention, can be understood in detail, reference is had to the accompanying drawings, which form a part of this specification, and wherein:

FlG. 1 is an isometric View of a relay constructed in accordance with the invention, the cover thereof being illustrated in displaced position:

FIG. 2 is a plan view of the relay of FIG. 1, with the cover removed;

FIG. 3 is a sectional view taken on line 3-3, 'FIG. 2, with some parts shown in elevation;

FIG. 4 is a perspective view of a frame member forming part of the relay of FIG. 1;

FIG. 5 is a perspective view of one contact set of the relay of FIG. 1; and

FIG. 6 is a sectional view taken longitudinally through one of the electromagnets of the relay of PEG. 1 and showing a portion of the mounting means for the electromagnet, F168. 2, 4, 5 and 6 being enlarged, relative to FIG. 1, for clarity of illustration.

Referring now to the drawings, there is shown a miniature relay constructed in accordance with one embodiment of the invention and including a housing comprising In this embodiment, base lit is in the form of a relatively thin square plate. A groove 12 extends around base 10 adjacent to the side edges thereof and has a U-shaped transverse section which opens through flat surface 13 of base it As shown in FIGS. 1 and 3, cover 11 is hollow and of box-like configuration, one side thereof being open so that the cover includes an edge portion 11 dimensioned to be received in groove 12 so that base lit lies across the open side of the cover and the combination of base and cover therefore encloses the working structure of the relay. The cover 11 is hermetically sealed to base 1%, as by first filling groove 12 with solder and/or pretinning cover 11, then placing the cover in position, and applying heat so that the solder is fused and, upon cooling, seals the edge 11 of the cover in the groove 12.

A plurality of terminal pins 14 are affixed to base lit, each pin extending in a direction perpendicular to surface United States Patent 0 3,1ZLM8 Patented Feb. 11, 1984 "ice 13. Base 10 is provided with appropriate openings through which the pins extend, the space between each of the pins and the wall of its associated opening being filled by suitable insulation, such as glass, which rigidly secures the terminal to the base. As will be clear from comparison of FIGS. 1 and 3, all of pins 14 extend completely through base 10 so as to project from both major faces thereof. The pins 14 are spaced in a regular system of rectangular coordinates so as to extend in two parallel rows of four pins each. The adjacent pins in each row are spaced by equal distances and the two rows are spaced apart by this same distance. In the particular embodiment chosen for illustration, pins 14 can, for example, be spaced 0.2 inch between centers.

The relay also includes a pair of single pole, double throw, break-make contact assemblies 15 and 16, the two contact assemblies being identical so that only one need be described in detail. Contact assembly 15 comprises a pair of relatively fixed contact arms 17 and '18, and a movable contact arm 19 biased toward engagement with arm 18, each arm being fixed at one end to a diiferent one of pins 14 in the manner shown in the drawings. Each arm is in the form of an elongated, thin strip of a suitable contact spring metal and is bent into a generally V-shaped configuration. From its point of attachment to its associated terminal pin, each arm extends parallel to surface 13 of base 10, the free end of the contact arm thus being movable through an arc in a plane parallel to surface 13 and normal to the axes of pins '14.

The free ends of contact arms 17 and :18 are spaced apart to provide a separation through which the free end of contact arm in extends. The free end of arm 19 projects beyond the free end of contact arm 18 so that it can be engaged by an actuator in a manner hereafter described. Similarly, contact assembly 16 is provided with a pair of relatively fixed contact arms 20 and 21 and a movable contact arm 22 biased toward engagement with arm 21. Further details of the contact assemblies are disclosed and claimed in copending application Serial No. 79,065, filed concurrently herewith by Walter J. Richert and Hugh 0. Wells.

The power means provided for actuating contact assemblies 15 and 16 comprises a pair of electromagnets 23 and 24, a permanent magnet 25, and an armature 26 having fixed thereto a pair of actuators or pushers 27 and 28 en gaged with movable contact arms 19 and 22, respectively. Electromagnets 23 and 24 are substantially identical. As best seen in FIG. 6, electromagnet 23 includes a bobbin 29 having a pair of transverse end flanges 3t and a central tubular member 31 extending between the flanges. An energizing coil 3-2. is wound on the bobbin and is confined on the tubular member between the end flanges. Tubular member 3 1 provides the bobbin with an axial bore 33. A core 34, constructed from a suitable nonretentive magnetic material, extends through bore 33 of bobbin 29 and is provided at one end with a head of enlarged diameter, which forms pole piece 35, and at the other end with a tip of reduced diameter. Similarly, electromagnet 24 includes an energizing coil 36 and a core 37 having a pole piece 33.

As best seen in FIG. 3, cores 34 and 37 are interconnected, at the ends thereof opposite pole pieces 35 and 38, by a magnetic end plate 39 which has parallel side edges and rounded ends. The end plate is also provided with a pair of spaced openings into which the reduced tip portions of cores 3'4- and 37 are inserted, the cores being rigidly affixed to the end plate as by staking or by a tight press fit.

Electromagnets Z3 and 24 are rigidly affixed to base 16 in such positions that the electromagnets are parallel to one another and to surface 13 and extend in directions normal to the directions in which the rows of terminal ends 14 extend. The electromagnets Z3 and 24 are spaced apart and permanent magnet 25 is disposed therebetween. Permanent magnet 25 has a rectangular transverse cross section and is provided at one end with a beveled edge which forms a pivot edge it) for armature 2 6. The length of permanent magnet 25 is slightly greater than the length of either of the electromagnets so that pivot edge 44} projects beyond the exposed pole pieces and 33. The 'Width of permanent magnet'ZS is such that the permanent magnet, when properly centered between the two electromagnets, does not project laterally beyond the electromagnets.

Armature 26 is constructed from magnetic material and is provided with a V-shaped bend at a portion intermediate the ends thereof, the armature being both magnetically engaged with and pivotally mounted on pivot edge 44), the V-shaped bend being engaged by the pivot edge 40. The magnetic eifect of the permanent magnet is sufficient to hold the armature in place under normal conditiorrs. In order to secure the required pivotal action it is necessary that the angle of pivot edge 4% be less than that of the angle of the bend in the armature. The armature extends across the faces of pole pieces 35 and 38, the pivot edge 40 being located so that the armature canbe pivoted into engagement with either one or the other of the pole pieces but cannot simultaneously engage both.

Actuators 27 and 23 are identical and only one need be described in detail. Actuator 27 comprises a relatively rigid wire member secured at one end to the surface of armature 26 adjacent to the movable contact arm 19 and provided at the other end with a bead of suitable insulation material, the wire being suitably bent intermediate its ends to assure that, during movement of the armature, the actuator will not engage any adjacent elements of the relay other than contact arm 19.

The electromagnets 23 and 24 end plate 39' and perma nent magnet 25 are rigidly secured to base it} by means including a pair of brackets 41 and '42. As best seen in FIG. 4, bracket 41 is an integral, generally -T-shaped metal member including a first portion 43 and a second portion 4 4 which extends laterally in both directions from portion 43. Gn each side of portion 43, portion 4 4 is provided with a pair of flanges 45 and 4 6 which lie in a common plane and extend perpendicular to the pla es of portions and 4-4. Portion 44 lies in a plane which is spaced from the plane of portion 43 in a direction which is opposite to that in which flanges 45, 46 project and is therefore toward fiat surface'm when the relay is assembled. Bracket 41 is secured to base it) by welding; portion 4 4 at two points indicated at $7 and by welding portion 43 to the top of a projection 4t? which extends from base 10 for a distance equal to approximately the distance between the planes of portions 43 and 44. Projection id is commonly referred to as a 'weld dimple and it will be understood that the welding operation causes the metal of the projection id to be fused to the metal of portion 43 of the bracket. In this connection, the portion =44 is provided with two dimples each located at one of the points 47 and projecting in a direction such as to engage surface 13 when the parts are in assembled relation. FIG. 3, for purposes of clarity, illustrates projection '48 and the dimples at points 47 as they exist prior to welding.

Permanent magnet 25 is disposed with one of its side surfaces extending along the face of portion 43 opposite projection 48, the width of portion 43- being' approximately equal to thecorresponding thickness of the permanent magnet. Likewise, the distance between adjacent e ge-s of flanges 45 and 46 is approximately equal to the corresponding dimension of the permanent magnet. Portion 43 is provided with a pair of transversely opposed cars 49 which project at right angles to the planethereof and engage adjacent side surfaces of permanent magnet 25. Thus, flanges 45 and 4 6 and ears prevent lateral shifting of the permanent magnet disposed thcrebetween. The end of portion 5a away from end plate 39 extends beyond flanges 45 and 4 6 and includes a tip 54; which overlies armature 26 and prevents the armature from being moved from operative engagement with pivot edge 4d. Portion 43 also includes an oval shaped aperture 53 through which solder is introduced when bracket 41 and permanent magnet 25 are secured together by soldering.

Each of flanges 4-5 and 46 is provided with a circular opening 59 through which the end of one of cores: 34 and 37 extends, so that the pole pieces 35, 3 8 he on the side of the flanges adjacent to the armature. The end of portion 43 opposite portion 44 is outwardly tapered and is provided with a pair of ears 51 which, prior to assembly, are slightly bent out of the plane of portion 43. End plate 39 is provided with a pair of opposed, shallow, outwardly opening notches 52, the distance between the side walls of each notch being slightly greater than the distance between the ends of ears 511. During assembly, the enlarged end of portion 43 disposed in one of notches 52, the end portion being Welded, in any suitable fashion, to end plate 3 9 so that the Weld occurs between cars 51 and the notch associated therewith. A spring washer 60 (FIG. 6) is placed between each of the bobbins and flanges 45 and 46 to prevent end play, i.e., movement of the bobbin axially along the core.

Bracket 42 is disposed on the side of permanent magnet 25 opposite to bracket 4-1 and includes a flat portion which extends along the adjacent side surface of the permanent magnet. Bracket 42 also has a pair of transversely opposed ears 55 which engage side portions of the permanent magnet in a manner similar to that by which ears 4? of bracket ll engage the magnet. End portion 56 of bracket 42 is disposed in the other of notches 52 of end plate 39. Also, bracket 42 has an aperture 57 through which solder is introduced when bracket 42 is secured to permanent magnet 25 and an end portion provided with a tip 61 Which extends toward tip 54 and 1 further aids in preventing movement of the armature away from the pivot edge.

The structure thus far described readily lends itself 7 to a simple assembly procedure. The terminal pins 14 are affixed to base it and th contact arms are then mounted upon the terminal pins. Electromagnets 23, 24, end plate 39, permanent magnet 25, brackets 41 and 52, armature 2d and spring washers 5b are then assembled, the end plate being fixed to cores 34, 37 so that the bobbins are clamped tightly between the end plate and spring Washers db, it being understoodthat pole pieces 35, 58 are forced into tight engagement with flanges 45, 46 when the cores are fixed to the end plate. Brackets id, 42 are welded to the end plate and the permanent magnet 25 is soldered to the rackets, it being understood, of course, that the position of permanent magnet 25 is adjusted, prior to soldering, to provide the desired armature gap. Thus, the electromagnets, the permanent magnet and the brackets are now rigidly interconnected as a unit, the armature being retained by the magnetic effect of the permanent magnet This unit is now placed in proper position on base 159, with portion 43 resting on projection 43 and with the dimples at points 47 engaging the face 13 of base it Bracket 4-1 is now fixedly secured to base it by resistance welding, with one electrode set engaging the surface of base ltl opposite face 13, at points aligned,

with the w'eld'dimples at 4 7 and 4 S, and with another electrode engaging bracket 42 above projection Gperation of the embodiment of the relay illustrated in FIGS. 1-6 and described above will be understood in complete detail from United States Patent No. 2,955; 174, Walter J. Richert, issued Uctober' 4, 1968. With referenceto this patent, it will be understood that a relay of this type can be designed for several specific modes of operation. Thus, the relay can be so designed that the peri.ai1ent magnet is effective to latch the armature in both of its extreme positions, or to accomplish such latching in only one selected extreme position. 7

V in atypical V iliSidllCC, the coils 32, 36 can be connected in series and wound in such fashion that one of the electromagnets will attract the armature while the other repels the same. Then, current flow through the series-connected coils in one direction will cause the armature to pivot into engagement with one of the pole pieces 35, 38, and current flow in the opposite direction will cause the armature to pivot into engagement with the other of the pole pieces. Pivoting of the armature to either of its extreme, pole piece-engaging positions results in movement of the corresponding one of the movable contact arms 19, 22 so that that one arm is disengaged from the lower (as viewed) relatively fixed contact and engaged with the upper relatively fixed contact. This switching action is effected by engagement of the movable contact arm by the corresponding one of the actuators 27 and 28, carried by the armature. During such operation, that one of the movable contacts Which is actuated is resiliently distorted and, accordingly, a resilient biasing force is established tend ing to return the armature. Assuming that both pole pieces are disposed for direct engagement by the armatures, magnetic latching occurs in both extreme positions of the armature and the magnetic effect of the permanent magnet is made sufiiciently great that the resilient biasing force developed in the movable contact arm is not adequate to disengage the armature from the pole piece to which it is magnetically latched. Thus, the relay remains latched after the electromagnets are deenergized. Upon energization of the electromagnets in the opposite sense, the combined eitect of the electromagnets and the resilient biasing force is sufficient to actuate the armature positively to the other of its extreme position.

While, for purposes of simplicity of illustration, only one particularly advantageous embodiment of the invention has been shown and described, it will be apparent to those skilled in the art that various modifications and changes can be made in the details and arrangement of the parts Without departing from the scope of the invention defined in the appended claims.

What is claimed is:

1. In a miniature relay capable of being plugged in a socket and characterized by minimized height in a direction away from the socket, the combination of a flat rectagular base;

a plurality of terminal pins extending through said base perpendicular to the major faces thereof,

said pins being spaced in a regular system of rectangular coordinates over a first portion of said base adjacent one edge thereof,

said pins projecting from both major faces of said base;

a contact assembly comprising a plurality of resilient contact members each secured to a different one of said pins,

said contact members all being disposed on the same side of said base;

a motor structure comprising two spaced eleetromagnets each having an elongated core of magnetic material, said electromagnets being disposed side-by-side with said cores parallel to each other and each having an exposed pole portion,

an elongated permanent magnet disposed between said electromagnets and having a pole portion at least generally between said exposed pole portions of said coils,

means magnetically interconnecting said permanent magnet and said cores at the ends thereof opposite said pole portions, and

a magnetic armature; and

a nonmagnetic mounting bracket securing said motor structure to said base in a location such that said electromagnets and permanent magnet extend paraliel to said base between said first portion and the edge of said base opposite said one edge thereof, with said exposed pole portions adjacent said contact assembly and said armature disposed between said electromagnets and said contact assembly, said bracket comprising a first port-ion extending parallel to said base and secured thereto, said first portion extending between said electromagnets,

a second portion, said second portion including upright portions projecting at right angles from said base,

each of said upright portions having an opening through which a different one of said cores extend adjacent said pole portions;

said second portion of said bracket being secured to said base at a location between said first portion of said base and the edge of said base opposite said one edge thereof.

2. A miniature relay in accordance with claim 1 in which said second portion of said mounting bracket includes other portions integral with said upright portions and extending parallel to and in contact with that major face of the base on which the electromagnets are mounted;

said other portions of said bracket being secured to said base.

3. A miniature relay in accordance with claim 2 in which said other portions of said bracket project from said second portions in a direction away from said one edge of said base.

4. A miniature relay in accordance with claim 1 in which said base has a projection extending from that face on which the electromagnets are mounted, and

said first portion of said bracket is secured to said projection so that said first portion is spaced from and is parallel to said base.

References Cited in the file of this patent UNITED STATES PATENTS Richert Oct. 4, 1960 

1. IN A MINIATURE RELAY CAPABLE OF BEING PLUGGED IN A SOCKET AND CHARACTERIZED BY MINIMIZED HEIGHT IN A DIRECTION AWAY FROM THE SOCKET, THE COMBINATION OF A FLAT RECTAGULAR BASE; A PLURALITY OF TERMINAL PINS EXTENDING THROUGH SAID BASE PERPENDICULAR TO THE MAJOR FACES THEREOF, SAID PINS BEING SPACED IN A REGULAR SYSTEM OF RECTANGULAR COORDINATES OVER A FIRST PORTION OF SAID BASE ADJACENT ONE EDGE THEREOF, SAID PINS PROJECTING FROM BOTH MAJOR FACES OF SAID BASE; A CONTACT ASSEMBLY COMPRISING A PLURALITY OF RESILIENT CONTACT MEMBERS EACH SECURED TO A DIFFERENT ONE OF SAID PINS, SAID CONTACT MEMBERS ALL BEING DISPOSED ON THE SAME SIDE OF SAID BASE; A MOTOR STRUCTURE COMPRISING TWO SPACED ELECTROMAGNETS EACH HAVING AN ELONGATED CORE OF MAGNETIC MATERIAL, SAID ELECTROMAGNETS BEING DISPOSED SIDE-BY-SIDE WITH SAID CORES PARALLEL TO EACH OTHER AND EACH HAVING AN EXPOSED POLE PORTION, AN ELONGATED PERMANENT MAGNET DISPOSED BETWEEN SAID ELECTROMAGNETS AND HAVING A POLE PORTION AT LEAST GENERALLY BETWEEN SAID EXPOSED POLE PORTIONS OF SAID COILS, MEANS MAGNETICALLY INTERCONNECTING SAID PERMANENT MAGNET AND SAID CORES AT THE ENDS THEREOF OPPOSITE SAID POLE PORTIONS, AND A MAGNETIC ARMATURE; AND A NONMAGNETIC MOUNTING BRACKET SECURING SAID MOTOR STRUCTURE TO SAID BASE IN A LOCATION SUCH THAT SAID ELECTROMAGNETS AND PERMANENT MAGNET EXTEND PARALLEL TO SAID BASE BETWEEN SAID FIRST PORTION AND THE EDGE OF SAID BASE OPPOSITE SAID ONE EDGE THEREOF, WITH SAID EXPOSED POLE PORTIONS ADJACENT SAID CONTACT ASSEMBLY AND SAID ARMATURE DISPOSED BETWEEN SAID ELECTROMAGNETS AND SAID CONTACT ASSEMBLY, SAID BRACKET COMPRISING A FIRST PORTION EXTENDING PARALLEL TO SAID BASE AND SECURED THERETO, SAID FIRST PORTION EXTENDING BETWEEN SAID ELECTROMAGNETS, A SECOND PORTION, SAID SECOND PORTION INCLUDING UPRIGHT PORTIONS PROJECTING AT RIGHT ANGLES FROM SAID BASE, EACH OF SAID UPRIGHT PORTIONS HAVING AN OPENING THROUGH WHICH A DIFFERENT ONE OF SAID CORES EXTEND ADJACENT SAID POLE PORTIONS; SAID SECOND PORTION OF SAID BRACKET BEING SECURED TO SAID BASE AT A LOCATION BETWEEN SAID FIRST PORTION OF SAID BASE AND THE EDGE OF SAID BASE OPPOSITE SAID ONE EDGE THEREOF. 